An active production tank battery and adjacent unlined brine pit at site B on the shores of Skiatook Lake, Okla. The brine pit receives water co-produced with oil, which is pumped from the pit and disposed of. Occasional overflows due to pump failures have created a salt scar, which extends from the pit to the lake. Photo courtesy of the U.S. Environmental Protection Agency

In addition to produced water (brine) the brine pit at site B also receives oil from broken pipes and tank leaks. All the produced fluids (oil and water) at the site are collected and separated in the tank battery adjacent to the brine pit

A multidisciplinary team of USGS scientists is developing methods to assess salt scars, such as this one at Site B, by Skiatook Lake, Okla., and salt impacted soils. The information from such assessments is needed to assess the extent of contamination and the cost of remediation

Site B is an active oil production field on the shores of Skiatook Lake, Okla. USGS scientists are studying the fate and effects of the past disposal and recent spills of produced water at the site. Salt scars extend from the tank battery on the left to the edge of the lake

Site B is a small but active oil production site with several pump jacks like this one. A multidisciplinary team of USGS scientists and their partners are studying the long-term and short-term effects of hydrocarbons and the constituents of produced water on the local environment a two sites (A and B) on the shores of Skiatook Lake, Okla.

Salt scar area below the brine pit at Site B's active tank battery. The salt scar had been remediated and revegetated in November 1999; however, most of the grasses have since died and erosion has started again. Skiatook Lake, Okla., can be seen in the background

USGS scientists have installed monitoring equipment (wells, rain gage, sampling line) to collect water-quality data on a salt scar that extends from a brine pit (pit and berm in foreground) to Skiatook Lake, Okla. (in background). The brine in this pit at Site B is pumped into collection tanks by a submersible pump, but in the past the pumping system has occasionally failed, causing overflow of the brine pit

Salt-scarred and oil-stained slope above the main tank battery at Site B, Skiatook Lake, Okla. Grass fires have occurred in the area, which damage nonmetal production lines

View of a tank battery, injection well site, and brine pit (on the right in the picture) at Site B, Skiatook Lake, Okla. An older tank location is on the left in the picture. Salt scars extend from both sites to the lake

Site B on the shores of Skiatook Lake, Okla., is still active, and has a tank battery containing produced water (brine) and oil. The brine is disposed of in the subsurface with this onsite injection well (one of two). Deep-well injection regulations require that injection wells be completed in aquifers with total dissolved solids greater than 10,000 mg/L (milligrams per liter)

An abandoned oil and tar pit at Site A, by Skiatook Lake, Okla. In the past sludge from processing and storage tanks was disposed of in shallow pits

Prior to environmental regulations in the 1970s, produced water was sometimes disposed of by discharging the water on the ground, which could cause salt scars such as this one at Site A, by Skiatook Lake, Okla.

An aerial view of the salt scar at Site A, Skiatook Lake, Okla., taken during 2004 data-collection activities. Major oil production activities ceased approximately 65 to 70 years ago; however, a salt scar persists to the right (north) of the road. The salt scar was cased by intentional or accidental releases of produced brine. Photo courtesy of the U.S. Environmental Protection Agency

View from the lower part of Site A's main salt scar looking south uphill toward the beginning of the scar. Seepage of salt water from a shallow sandstone aquifer continues, and active salt scarring persists. This area drains into the Cedar Creek arm of Skiatook Lake, Okla.

The lower part of Site A's main salt scar looking north to Skiatook Lake, Okla. The small white patches in the foreground are salt accumulations. These salt accumulations can wash into the lake in surface runoff during rain events

Salt scar downhill from the remains of two brine pits at Site A by Skiatook Lake, Okla. Grasses and weeds have partly revegetated the area. Grasses are sparse, however, and only grow where the salt content of the soil is not high

Highly saline produced water that was disposed of at Site A by discharging the water on to the ground caused salt scaring and subsequent erosion. Here the maximum depth of erosion is about 2 meters. Saline water seeps to the surface in the middle of the photo and flows to Skiatook Lake, Okla.

The discharge of produced water on the surface caused extensive erosion of the land surface and etching and pitting of sandstone bedrock at Site A, by Skiatook Lake, Okla.

Highly degraded and weathered oil residues from leaks and spills from pipelines and tank batteries are present at Site A, Skiatook Lake, Okla. Microbial action, volatilization, and water washing are most likely responsible for the transformation of spilled oil to the asphaltic and weathered oil observed at the site

Abandoned well at Site A by Skiatook Lake, Okla. Improperly sealed, abandoned wells may act as conduits that allow the flow of high saline water into shallow aquifers and onto the surface

A large band wheel once provided power to pump multiple production wells at Site A, Skiatook Lake, Okla. Attached to the wheel's hub were steel rods connected to outlying pump jacks. The rods ran back and forth through wooden guides mounted in metal posts. Several posts can be seen behind the rim of the wheel